examples: Remove heap allocation from C++ examples

Cleanup of UPM C++ examples.  Switched from heap allocation to
stack allocation when possible.  This simplifies the samples since it
removes the need for explicit memory management.  A script was used to
identify and replace pointer use.  To simplify the replace script, I
re-formatted the C++ examples using the UPM .clang-format file.
Unfortuantely this changes the look of the UPM C++ examples to a large
degree.  However, examples will now have a standard look/feel and
uniform formatting.

    * Ran clang-format w/provided UPM .clang-format file
    * Removed new's/delete's whenever possible (left those in interface
      examples)
    * Added IIO sensor library implementation of callback void* arg
    * Converted all sleeps to upm defined delays (added header when
      necessary)
    * Scrubbed CXX example includes

Signed-off-by: Noel Eck <noel.eck@intel.com>

examples/c++/ppd42ns.cxx

@@ -22,45 +22,44 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <unistd.h>
 #include <iostream>
 #include <signal.h>
+#include <string>
+
 #include "ppd42ns.hpp"
 
 using namespace std;
 
 int shouldRun = true;
 
-void sig_handler(int signo)
+void
+sig_handler(int signo)
 {
     if (signo == SIGINT)
         shouldRun = false;
 }
 
-
-int main ()
+int
+main()
 {
     signal(SIGINT, sig_handler);
 
-//! [Interesting]
+    //! [Interesting]
     // Instantiate a dust sensor on GPIO pin D8
-    upm::PPD42NS* dust = new upm::PPD42NS(8);
+    upm::PPD42NS dust(8);
     ppd42ns_dust_data data;
     cout << "This program will give readings every 30 seconds until "
-         << "you stop it"
-         << endl;
-    while (shouldRun)
-    {
-        data = dust->getData();
+         << "you stop it" << endl;
+    while (shouldRun) {
+        data = dust.getData();
         cout << "Low pulse occupancy: " << data.lowPulseOccupancy << endl;
         cout << "Ratio: " << data.ratio << endl;
         cout << "Concentration: " << data.concentration << endl;
         cout << endl;
     }
-//! [Interesting]
+    //! [Interesting]
 
     cout << "Exiting" << endl;
 
-    delete dust;
     return 0;
 }